June 07, 2013

Antarctica’s mountains, concealed for more than 30 million years under miles of ice, have now been exposed in a new map and video released June 5 by NASA. Using a new tool created by the British Antarctic Survey (BAS) called Bedmap2, researchers created the map by compiling decades worth of geophysical measurements of the icy continent, including surface elevation, ice thickness, an bedrock topography.

There are two major ice sheets on Earth, the one covering Greenland and the other over the Antarctica land mass. “Ice sheets grow because of snow, and like honey poured on a plate, spread outward and thin due to their own weight,” said Sophie Nowicki, an ice sheet scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Computer models allow ice sheet researchers to create different simulations of how ice sheets will respond to variations in air and ocean temperatures, giving them the opportunity to test many climate scenarios. According to IceBridge project scientist Michael Studinger, it is necessary to know details about the shape and structure of the bedrock lying beneath the ice in order to accurately to simulate the ice sheet’s dynamic response to such changing environmental conditions as temperature and snow accumulation.

Bedmap2, an improvement over the original Bedmap produced over a decade ago, is more precise, has higher resolution, and provides more coverage of Antarctica than its predecessor, according to NASA’s statement. Using data from satellites, aircraft, and surface-based surveys, scientists were able to produce a map with tighter grid spacing that includes many previously unseen surface and sub-ice features of the continent. In addition, NASA said that the increased use of GPS data in recent surveys improved the precision of Bedmap2. The improved precision of the new dataset will lead to more accurate measurements of ice volume and the potential contribution to rises in sea levels.

While Bedmap2’s ice volume and sea level calculations are similar to those found by the original Bedmap, it has provided increased estimates of Antarctica’s average bedrock depth, deepest point, and ice thickness. According to BAS scientist and lead author Peter Fretwell, the Bedmap2 data gives scientists a better knowledge of the sub-glacial environment and the Antarctic ice sheet.

“It will be an important resource for the next generation of ice sheet modelers, physical oceanographers, and structural geologists,” Fretwell said.

Researchers relied heavily on data obtained by NASA’s Ice, Cloud, and Land Elevation Satellite, known as ICESat, for their surface measurements and NASA’s Operation IceBridge, which collects data on ice thickness.

The results of the study were published February 28 in the journal The Cryosphere.

The Milankovitch cycle has a interval of approximately 100 thousand years and each peak represents a short warm period while a low is a glaciation. At present we are experiencing a short warm period between glaciations and if we are lucky human activity can divert this obvious problem coming in the future. There have been many glaciations in the last 30 million years and it has had a huge impact on forming the global geography. I think that this would have been worth mentioning in this article and is the real threat to existing ecosystems as they become more restricted to equatorial locations in the future. It is ironic that people are worried about the threat of global warming when the future without human technological intervention promises a era of low biomass as the world freezes again.